We just talked about your system’s structure. Now let’s discuss how you store your content.
We create a Johnny.Decimal number by taking our category, adding a decimal, and then a number, starting from
So the first item in our
16 Travel category was
16.01 Singapore, Jun 2022.
The next item gets the next ID:
16.02 Travel insurance. And so on.
So what is an ID?
This is a crucial concept: what exactly is an ID? How much should they contain? How granular should they be?
An ID is a unique thing: a job, a task, a reference, a meeting, an artefact.
Let’s look at a couple of examples.
The trip to Singapore
We’ll start with a simple, small example: your trip to Singapore.
Think about the artefacts you generate when you go on holiday. You have to book a flight and a hotel, and you might research what you want to do when you get there.
The trip is one Johnny.Decimal ID.
You might save:
- A PDF of the hotel booking, in your file system.
- The flight confirmation, in your email.
- Notes about what you want to visit, in your notes app.1
Your travel insurance
We’ve seen that your travel insurance folder,
16.02, holds two documents: your policies for the last two years.
But you were unlucky in Singapore and broke your leg. You need to make a claim and it’s reasonably complex. There are hospital bills, an extended hotel stay, and flight changes.
You could store all of this documentation in
16.02 Travel insurance, but this feels like a new thing. So we should give it its own ID.
That ID might end up looking like this.
Avoid creating subfolders
Ideally, you do not create any folders inside a Johnny.Decimal folder.
Because if you do, it’s easy to end up in a mess again. The whole point of this is that everything is well defined: folders-in-folders ruins it all.
But sometimes a limited number of subfolders makes sense. In the example above, we could have saved all the documents in the main folder. But it was neater to create a few subfolders.
If it ever feels like it’s getting out of hand, split the thing in to multiple IDs.
Naming your IDs
When naming things, remember that you’re already in the context of a category. So you don’t need to be explicit.
16.01 wasn’t named
Trip to Singapore, Jun 2022. It’s in our
16 Travel category, so we know it can only be related to travel.
What happens when I use all 99 IDs?
You never will.
And if you do, the category you defined was probably too broad. Split it up.